Angular and linear position systems are widely used in automatic control systems as feedback-sensing devices in one or more control loops of the system. In the automotive industry, a relatively recent trend is providing control-by-wire in lieu of the more traditional control provided by mechanical linkages, such as cables, rods and the like.
With the goal of improving drive stability of automotive vehicles, mechanically assisted driver control has been studied as a way to reduce uncontrolled vehicle behavior, such as body yaw and roll, as well as skidding. Specifically, antilock braking systems has already come into use as means for preventing locking of the wheels during breaking. Additionally, there are proposed vehicle control systems such as traction control, which reduces wheel spin during acceleration, or vehicle stability control, which affords overall control of stabilization of vehicle behavior.
In recent years, various vehicular height regulator systems or vehicular height control systems have been developed for regulating vehicle body attitude. For example, one such vehicle height control system is disclosed in U.S. Pat. No. 4,838,563 to Konishi et al.
For providing accurate vehicular height control, it is essential that the vehicle height indicative signal generated by the vehicle height sensor accurately correspond to the actual height of the vehicle body. In order to make the vehicle height indicative signal value accurately correspond to the actual height, accurate alignment of the vehicle height sensor in mounting the sensor on the vehicle body becomes essential.
In the conventional process to adjust alignment of the vehicle height sensor in mounting the sensor on the vehicle body, a pivotal arm of a vehicle height sensor is fixed at a certain angular position, at which the sensor produces a vehicle height indicative signal indicative of the vehicular height coincident with a preset target vehicle height, by means of a pin. At this condition, the vehicle height sensor is fixed onto the vehicle body. Thereafter, a test load is applied to the vehicle body to adjust the vehicle height so that the height level of a suspension member, such as a suspension link or suspension arm, becomes equal to the highest level of the arm of the vehicle height sensor. Then, the sensor arm and the suspension member are rigidly connected for cooperation with one another. Thereafter, the shearing load is exerted on the pin to shear the pin to release the sensor arm from restriction. Also, the test load exerted on the vehicle body is released.
Such conventional processes require additional parts, such as a pin for fixing the sensor arm relative to the sensor body, and an additional jig for applying the test load. Furthermore, the aforementioned process requires substantial attention to cause lowering of efficiency in adjusting alignment of the vehicle height sensor, further increasing costs.
More recently, position sensors have come into use in a wide variety of related applications, such as such as determining the relative movement of a vehicle suspension system with respect to a supported vehicle body. Conventional suspension-type position sensors typically include a linear-type motion sensor that utilizes capacitor plates or an inductor to determine the distance between a component of the vehicle suspension system and the vehicle body.
Heretofore, the sensors and mechanical linkages used in connection therewith to determine the relative movement of a vehicle suspension system with respect to a vehicle body have been limited by the construction being placed within the respective vehicle in a location, which provides only linear of the vehicle suspension system with respect to the vehicle body. These placement limitations are a result of not only the construction of the sensor itself, but also of the mechanical linkages used to connect the sensor to a component of the vehicle suspension system and a component of the vehicle body.
Currently, electronically controlled suspension systems often require semi-active suspension systems or active suspension systems to provide active damping for a vehicle. In such suspension systems, sensors supply input signals, including vehicle suspension position, to an electronic control unit on a real time basis. This increased functionality requires that more and more sensors be incorporated within the vehicle body and suspension system, making sensor packaging, as well as cost, complexity and robustness, more and more problematic.